Sealing the Joints and Edges of a Roof Terrace

1. A crumbling surface

At the foot of the railings the old coating had broken up and the material underneath was crumbling.

2. The parapet

On top of the parapetParapetThe low wall around the edge of a flat roof or balcony. The joint between it and the floor is one of the most common places for leaks., too, the renderRender (plaster)A layer of mortar (sand, cement or lime, and water) spread over brick or concrete to give a wall a straight, sound surface ready for paint or tiles. had flakedPeeling paintWhen paint loses its grip and lifts off in flakes or sheets. It is almost always a sign of a problem underneath, usually damp or poor preparation. away and was letting water into the wall.

3. The roof before

An old, stained surface, divided into squares by joints.

4. Corners first

The joint between floor and parapet is covered with white waterproofingLiquid waterproofing membraneA waterproofing product applied as a liquid by roller, brush or spray. Once dry it forms one continuous, flexible membrane with no seams. that rounds off the corner and runs up the wall.

5. The joints

The joints across the roof are sealed with white strips, because that is where the surface moves and opens up.

6. Around obstacles

The base of the satellite dish and the corners around it are covered with no gaps.

7. Along the railings

The white strip runs all the way round the edge and links up with the joints.

8. The result

Perimeter and joints sealed. The places where water used to get in are now closed.